1. Field of the Invention
The present invention relates to an all-solid-state electrode body and an electrochemical cell.
2. Description of the Related Art
With regard to an electrochemical cell (a secondary battery, a capacitor, and the like) which are used as a power supply of various kinds of devices, a configuration, which is provided with an electrode body and an exterior packaging body in which the electrode body is accommodated, is known.
For example, the exterior packaging body includes a first substrate, a second substrate, and a sealing member that joins the first substrate and the second substrate. The first substrate, the second substrate, and the sealing member partition a cavity in which the electrode body is accommodated.
The electrode body has a configuration in which a positive electrode layer and a negative electrode layer are alternatively stacked with an electrolyte interposed therebetween. The positive electrode layer includes a positive electrode current collector layer that is disposed at a first end in a stacking direction in the electrode body. The positive electrode current collector layer is conducted to an outer side via a conductive portion that is formed in one substrate of the above-described substrates.
The negative electrode layer includes a negative electrode current collector layer that is disposed at a second end in the stacking direction in the electrode body. The negative electrode current collector layer is conducted to an outer side via a conductive portion that is formed in the other substrate of the above-described substrates.
As the above-described electrode body, for example, as disclosed in Japanese Unexamined Patent Application, First Publication No. 2013-243006, a so-called all-solid-state electrode body, in which a positive electrode layer and a negative electrode layer are alternately stacked via a solid electrolyte, is known.
In the all-solid-state electrode body, there is no concern of leakage or depletion of the electrolyte, and the like differently from an electrode body that uses a liquid electrolyte or a polymer electrolyte, and thus the all-solid-state electrode body has an advantage that a long operational lifespan can be realized.
In an electrochemical cell that uses the all-solid-state electrode body, it is necessary to bring the conductive portions of respective substrates, and the positive electrode current collector layer and the negative electrode current collector layer of the electrode body into close contact with each other so as to secure conductivity. In this case, it is preferable that the positive electrode current collector layer is connected to the conductive portion of one substrate, for example, via a conductive adhesive, and the negative electrode current collector layer is connected to the conductive portion of the other substrate, for example, via a conductive adhesive.
However, in the configuration of the related art, it is difficult to respectively connect both of the positive electrode current collector layer and the negative electrode current collector layer to the conductive portions of the substrates via the adhesive and the like. Specifically, in the configuration of the related art, it is necessary to respectively connect the positive electrode current collector layer and the negative electrode current collector layer to different substrates at both ends in a stacking direction. According to this, when both of the positive electrode current collector layer and the negative electrode current collector layer are respectively connected to the conductive portions of the substrates with an adhesive, it is difficult to completely remove a solvent of the adhesive. In this case, the exterior packaging body is sealed in a state in which the solvent remains. As a result, there is a concern that battery characteristics may deteriorate due to the solvent that remains in a cavity.
The electrode body is expanded and contracted during charging and discharging. According to this, in a case where the electrode body is mounted in the substrates on both surfaces in the stacking direction, there is a concern that a great stress may act on the electrode body during charging.
An aspect of the invention has been made in consideration of the above-described situations, and an object thereof is to provide high-performance and high-reliability all-solid-state electrode body and electrochemical cell which maintain battery characteristics while securing conductivity.